Photographic material



Patented Aug. 1,1939

umrso STATES amuse I l rnorooaarmo MATERIAL Honor- Verkinderen, Hortael,near Antwerp, Bel-- glam, assignor to Gemrt Photo-Promoters ApplicationMay 14, 1931. Serial No. use w msmcramsylaiase IAsaruleeachottheselayersistora different part of the spectrum. Suchmulti-layer material is produced by pouring one layer on top oi theother. It is however known that the separation oi the w rmed layersencounters ditilculties which could hitherto not be overcome entirely.It has already been suggested to arrange between adjoining layers a thinintermediate support, which can readily be stripped. However in view ofthe fact that such intermediate support must a certain thickness, one orthe other or the light-sensitive layers, when the material is exposed inthe camera, will be out focus and in consequence thereof an indistinctimage will be produced. One has also suggested to insert between thelight-sensitive layers very thin layers of coliodium or similarmaterial, sincesuoh lay- .ers, similarly as the intermediate supportsmen! tioned above, are adapted to facilitate the stripping of thelight-sensitive layers and, in contrast negative from teing damaged anddeformed when the part negatives are stripped Inthe photographicmaterial aomrding to the present invention a plurality of layers aresuperposed in such manner that the light-sensitive layers eachconsisting of a binder such as gelatine and a light-sensitive substancesuch as a silver halide suspended therein are arranged in closestsuperposition, so that the production oi sharp and distinct images isguaranteed. Moreover these layers can be separated easily and withoutany danger of a negative being damaged.

In accordance with this invention the new material comprises,intermediatebetween the lightsensitive layers, fusible intermediatelayers, the

,melting temperature of which lies within a and below the temperature atwhich the lightsensitive layers'and/or their support would be may also(01.. es-zl a damaged or the multi-layer material were exposed tothistemperature for a short part oftime.

I prefer pr intermediate layers melting at diiierent temperatures andarranging the intel-mediate layers in such manner that the meltingtemperatures rise in the direction from the top layertowards the supportor carrier, 1. e. an intermediate layer farther remote from thesupmedlate layers may for instance be wax, paratfln, fatty substances.natural or artificial resins, etc.

. I have found that the intermediate layers may be poured with extremethinness (below microns and preferably about-24 microns), and will stillbe able to serve my purpose.

port will have a lower melting point than an in-' termediate layernearer to the support.

The material constituting the fusible inter-j I may choose the materialfor the intermediate layers in such manner that the refractive index Iof the intermediate layer: and that of the binder forming part of thelight sensitive layers are about the same so that in this manner theoptical contact between the light-sensitive layers is assured.

In the drawing photographic material embodying my invention isillustrated diagrammatically by way of example in cross section, drawnto a greatly enlarged scale. The material here shown is a negativematerial of a kind adapted for use in three-color photography. I

ierring to the drawing, l is the support, which may be glass, Celluloid,cellulose acetate, w ,9 or some other suitable material and 2, 3 and tare three light-sensitive layers. The layer 2 is sensitised for red,layer 3 for green-yellow.

r I is not sensitlzedand therefore only bluetivei Between the layers 2and 3 is arranged a very thin parai'nn layer 5 melting at about 70 C.Between the layers 3 and! is arranged a similarly very thin paramn layerC, which melts already at about t0 C. In order to prevent blue rays fromreaching the light-sensitive layers 3 and I, the intermediate layer 8and/or the light sensitive layer I may contuin a yellow colorillter-dyestuff. In order to prevent certain rays from penetrating thelayer 3 and reaching the layer 2, the'layers 3 and/or I containcorresponding color fllter dyestufls.

The light-sensitive layer 2 may be replaced by a panchromatic emulsionsensitized for the entire "spectrum and in that case a red color filterdyestuii in the intermediate layer 5 may prevent other than red raysfrom reaching the light-sensitive layer 2.

Obviously the light-sensitive layers may be supposed in differentsequence than shown in the drawing and it is also powble to so form thenew material that it is able to satisfy the many differ- 5 entconditions to be fulfilled by a color photogra- I phy material. Thus forinstance the layer 2, which is sensitive for blue and red, may bearranged on top and in this case the sensitivity of this layer for bluemay be reduced by well-known means. It is however also possible toobtain a copy from the red part-negative without reducing separately ontransparent supports which may for instance be coated with a gelatinelayer to which may be admixed substances adapted to facilitate thepasting-on of the light-sensitive layer. Instead of gelatine also othersubstances facilitating the fixing of the-light-sensitive layers may beused. In the case, where the material is designed for use incinematography, it is preferable to use, for the individual layers,supports possessing the same properties (shrinkage limits etc.) as thesupport of the multi-layer material.

I have also found it advantageous to use in- 5 dividual supports havingperforations of the same dimensions as the support of the multilayermaterial in order that on transferring the individual layers onto theirindividual supports the perforations of these layers and oftheir 44)supports are in exact register. In' view of the necessity of providingperforations of identical dimensions -in the original support and in thesupports for the individual layers it appears desirable that themanufacturer who produces the 45 multi-layer material, provide hiscustomer also with the corresponding number of supports for.

the part-layers. These part-supports should, if possible, be formed fromthe same batch as the multi-layer support in order to possess the sameproperties as this support. Therefore when selling a material such asshown onthe drawing, this material shall preferably be accompanied bytwo transparent supports designed to take While up the light-sensitivelayers I and 4. these layers are then transferred onto these newsupports, the light-sensitive layer 2 remains on the original support I.

The light-sensitive layers may be separated from each other andtransferred onto their in- 50 dividual supports in the following manner:

In order to transfer the layer 4 onto one of the individual transparentsupports provided for s this purpose, the gelatine layer, which may bearranged on this support, is moistened and the layer 4 pressed onto thegelatine layer in such manner as to firmly adhere to it. Now themultilayer negative as a wholetogether with the transparent individualsupport adhering to it is heated to'about 45-50 0., whereby the paramnlayer 8 is caused to melt. The transparent individual support may now beremoved together with thelight-sensitive layer 4. I thus obtain theoriginal negative material, from which the top layer 4 is removed, andon the other hand the combination of this layer with a transparentsupport. As a rule a thin layer of paraffin adheres to both. As far assuch fusible layers still adhering to the articles are soluble, they arenow removed by means of appropriate solvents, wellknown in the art,which, whiledissolving the 5 fusible substance, are unable to exert anob noxious influence on the light-sensitive layers or on their support.Similarly as the layer 4 also layer 3 is separated from the multi-layermaterial and transferred onto a transparent support. 10 However in orderto cause the paraffin layer I to melt the multi-layer material must beheated to about 75-80 C. Since the light-sensitive layer 2 remains onthe original support I, there re- 5 sult at the end of the separatingoperation three separate supports carrying the light-sensitive layers 2,3 and 4 respectively, each of which can new photographic material mayalso comprise only two such layers arranged in superposition on a commonsupport. The third light-sensitive layer may be arranged on a separatesupport and go may be used together with the two-layer material as abi-paclr. When using such negative materials, after exposure only one ofthe two superposed light-sensitive layers must be transferred onto atransparent support. However op- '5 erating with a bi-pacln involves thedisadvantages, that the light-sensitive layers must be exposed across asupport, that the contact between the light-sensitive layers is notsatisfactory and that a special kind of camera is re-. 0 quired for theexposure.

Obviously in photographic material according to this invention a greateror lesser number of light-sensitive layers th'anthree may be provided.Any such different material is used for producing more or less thanthree part-negatives.

The process according to this invention may readily be adapted to anymaterial. For instance if four part negatives shall be obtained, 0 thefour light sensitive layers may either be arranged on a common supportor, as in a bi-pack for three-color photography, be distributed on twosupports in such manner, that three layers are arranged on one support,the fourth layer 5 on another support. Alternatively the layers may bearrangedin pairs on two supports.

Various changes may be made in the details disclosed in the foregoingspecification without departing from the invention or sacrificing theadvantages thereof.

.1 claim:

l. A photographic material comprising in combination, a plurality ofsuperposed light-sensitive layers and a fusible intermediate layer beastween adjoining light-sensitive layers, the melting temperatureof thefusible layer being above the temperature which enables alight-sensitive layer to be arranged on the intermediate layer, andbelow the temperature at which the light- 70 sensitive layers would bedamaged if exposed to this temperature for a short time.

2. A photographic material comprising in combination, a support, aplurality of superposed light-sensitive layers arranged on said supportand a fusible intermediate layer between adjoining light-sensitivelayers, the melting temperature of the fusible layer being above thetemperature which enables a light-sensitive layer to be arranged on theintermediate layer, and below the temperature at which thelight-sensitive layers and said support would be damaged if exposed tothis temperature for a short time.

3. The photographic material of claim 1, in which a plurality of fusibleintermediate layers is provided, diiferent layers having diflerentmelting points.

4. The photographic material of claim 2, in which a plurality of morethan two light-sensitive layers is arranged in super-position with afusible layer between every two adjoining lightsensitive layers, themelting point of the fusible layer nearest to the support being higherthan the melting point of a layer farther away from the support. l

5. The photographic material of claim 2, in which a plurality of morethan two light-sensitive layers is arranged in superposition with afusible layer between every two adjoining lightsensitive layers, themelting points of the layers farther away from the support being lowerthan those of the layers nearer to the support.

6. The photographic material of claim 1, in which each light-sensitivelayer comprises a binder and a light-sensitive substance suspended insaid binder, the binder and the fusible layer having refractive indexesof the same order.

'7. The method of producing part images for color photography with theaid of a photographic multi-layer material which is a combination of aplurality of superposed light-sensitive layers and a fusible layerbetween adjoining light-sensitive layers, the melting temperature of thefusible layer being lower than the temperature at which the adjacentlight-sensitive layers would be damaged if exposed to this temperaturefor a short time, which comprises placing an auxiliary transparentsupport, coated with a binder, onto the topmost light-sensitive layer ofthe multilayer material, heating the multilayer material together withthe auxiliary support resting thereon to a temperature slightly abovethe melting point of said fusible intermediate layer and removing theauxiliary support together with the topmost light-sensitive layeradhering to it.

8. The method of claim 7 as applied to a photographic multilayermaterial being a combination of a plurality of light-sensitive layerswith a fusible intermediate layer between each two adjacentlight-sensitive layers, these fusible intermediate layers havingdifferent melting points, which comprises placing an auxiliarytransparent support, coated with a binder, onto the topmostlight-sensitive layer of the multilayer material, heating the multilayermaterial together with the auxiliary support resting thereon to atemperature slightly above the melting point of the fusible intermediatelayer adjoining the topmost light-sensitive layer, removing theauxiliary support together with the topmost light-sensitive layeradhering to it, placing another auxiliary transparent support, coatedwith a binder, onto the light-eensitive layer uncovered by the removalof the topmost layer, heating the multilayer material together with saidother auxiliary support slightly above the melting point of the fusibleintermediate layer adjoining said uncovered light-sensitive layer andremoving said other auxiliary support together with the uncoveredlight-sensitive layer adhering to it.

9. The process of claim 7, in which the multi-

